A blade server system packages servers onto single boards (server blades) that are housed in a chassis that provides access to shared resources such as power. A chassis management module operates to manage the shared resources among the server blades. Currently, when the server blade is booted to an operating system, it is unable to communicate with the chassis management module to exchange information about power events such as Advanced Configuration and Power Interface (ACPI) (published 1996) power states.
ACPI is an open industry specification that establishes industry-standard interfaces for operating system directed power management on laptops, desktops, and servers. ACPI enables an operating system to control an amount of power given to an entire computer system or specific devices attached to the computer system. To conserve energy while remaining quickly available, ACPI defines a number of sleep states known as S-states. An ACPI-compliant computer system may implement some or all of the defined S-states.
Commonly supported S-states include the S0, S1, S4, and S5 sleep states. The S0 sleep state is a state where all the devices on the computer system are on and no sleep is enabled. The S1 sleep state is a low wake-up latency sleep state. In the S1 sleep state, the computer system context in the processor and/or chip set is maintained. The S4 sleep state (non-volatile sleep state) is a special global system state that allows system context to be saved and restored relatively slowly when power is lost to the baseboard. The operating system writes system context to a non-volatile storage file and leaves appropriate context markers. The S5 sleep state is similar to the S4 sleep state except the operating system does not save any context nor enable any devices to wake up the system. The system is in the “soft” off state and requires a complete boot when awakened.
Currently, a server blade's operating system is unable to communicate ACPI sleep states to an off-board chassis management module responsible for power management. Thus, what is needed is a method and apparatus for communicating information from an operating system based environment of a server blade to the chassis management module.